Clemens, 26, has mopped up 98 innings for the Astros over the past two seasons and posted a 5.51 ERA with 6.0 K/9, 3.6 BB/9 and a 36.9 percent ground-ball rate in the process. Though he posted strong numbers through Double-A in his minor league career, he stumbled at Triple-A and has recorded a combined 5.91 ERA in 182 2/3 innings over parts of four seasons at that level.

The 27-year-old Martinez has logged 18 1/3 innings with Houston over the past two seasons with a 6.38 ERA and a 12-to-5 K/BB ratio in that time. He, too, has struggled at Triple-A, posting a 6.03 ERA over his two seasons (94 innings) with Oklahoma City.

Tropeano is the most notable prospect of the bunch, ranking 13th among Astros prospects on the midseason list compiled by Jonathan Mayo and Jim Callis of MLB.com. The 2011 fifth-round pick pitched to a 3.03 ERA with 8.7 K/9 and 2.4 BB/9 in 124 2/3 innings as a member of Triple-A Oklahoma City’s rotation this year. Callis and Mayo note that his low-90s fastball and changeup give him two above-average offerings, and his slider has the potential to be above-average as well. With the potential for three above-average offerings, Tropeano would seem to have a shot at being a rotation member in the future.